Enteric glia and visceral pain

摘要 腹痛是最常见的胃肠道问题，是功能性疼痛的主要原因。 胃肠疾病如肠易激综合征（IBS）和炎性肠病（IBD）。 尽管作出了广泛的努力，但在负责生产的机制方面仍然没有达成共识。 腹痛这种缺乏进展的情况反映在目前疗法的疗效差和治疗停滞。 腹痛的新型靶向治疗进展。本提案的总体目标是了解 敏感内脏神经纤维的机制，该提案的具体重点是机制 由肠神经胶质调节。神经胶质细胞在中枢神经系统痛觉传递的调节中起着重要的作用 系统，但如何之间的相互作用，神经胶质细胞和神经纤维在肠道有助于产生 内脏疼痛未知。这项提议验证了肠神经胶质细胞有助于内脏神经元的核心假设。 通过与伤害感受器的直接相互作用和通过调节免疫应答间接产生超敏反应。这 双重假设将在利用靶向遗传模型来操纵神经胶质的两个特定目标中进行测试， 建立内脏高敏感性动物模型，并进行光遗传学记录、免疫组化 测定，电生理学和内脏反射记录，以研究对感觉神经元活动的影响， 健康和疾病。目的1将验证肠胶质细胞直接调节内脏神经元活动的假设， 伤害感受器Specific Aim 1a将使用化学遗传学和基因敲除小鼠模型来研究 神经胶质递质释放和特异性Aim 1b将使用选择性药物和基因敲除小鼠来研究神经胶质递质的作用。 调节ATP和组胺可用性的胞外酶。目的2将检验肠神经胶质细胞 通过与免疫细胞的相互作用间接调节内脏伤害感受器。具体目标2a将使用 转基因小鼠和单克隆抗体，以研究胶质细胞与巨噬细胞的相互作用， 释放介质，包括ATP和M-CSF。Specific Aim 2b将使用基因敲除小鼠和单克隆 抗体来研究神经胶质细胞和淋巴细胞之间的相互作用， 由抗原呈递介导。目标2中的免疫应答将通过微阵列进行分析， 免疫组织化学和流式细胞术。这项研究的结果将确定胶质免疫的新作用， 与周围感觉神经元的相互作用。这一新的洞察机制，敏感的内脏 神经将促进功能性胃肠道疾病中腹痛的新疗法的发展 例如IBS和IBD。

ABSTRACT Abdominal pain is the most common gastrointestinal issue and is a major cause of suffering in functional gastrointestinal disorder such as irritable bowel syndrome (IBS) and in the inflammatory bowel diseases (IBD). Despite extensive efforts, there is still no consensus regarding the mechanisms responsible for producing abdominal pain. This lack of progress is reflected by the poor efficacy of current therapies and the stalled progress toward novel, targeted therapies for abdominal pain. The overall goal of this proposal is to understand mechanisms that sensitize visceral nerve fibers and the specific focus of this proposal is on mechanisms regulated by enteric glia. Glia play a central role in the regulation of pain transmission in the central nervous system, but how interactions between glia and nerve fibers in the intestine contribute to the generation of visceral pain is unknown. This proposal tests the central hypothesis that enteric glia contribute to visceral hypersensitivity by direct interactions with nociceptors, and indirectly by modulating immune responses. This dual hypothesis will be tested in two specific aims that utilize targeted genetic models to manipulate glia, established animal models of visceral hypersensitivity, and optogenetic recordings, immunohistochemical assays, electrophysiology, and visceromotor reflex recordings to study the impact on sensory neuron activity in health and disease. Aim 1 will test the hypothesis that enteric glia directly modulate the activity of visceral nociceptors. Specific Aim 1a will use chemogenetic and knockout mouse models to study the role of gliotransmitter release and Specific Aim 1b will use selective drugs and knockout mice to study the role of glial ectoenzymes that regulate ATP and histamine availability. Aim 2 will test the hypothesis that enteric glia indirectly modulate visceral nociceptors through interactions with immune cells. Specific Aim 2a will use transgenic mice and monoclonal antibodies to study glial interactions with macrophages mediated by the release of mediators including ATP and M-CSF. Specific Aim 2b will use knockout mice and monoclonal antibodies to study interactions that are secondarily dependent on interactions between glia and lymphocytes mediated by antigen presentation. Immune responses in Aim 2 will be analyzed by microarrays, immunohistochemistry, and flow cytometry. The results of this study will identify novel effects of glial–immune interactions on sensory neurons in the periphery. This new insight into mechanisms that sensitize visceral nerves will facilitate the development of new therapies for abdominal pain in functional gastrointestinal disorders, such as IBS and IBD.